Plasmonics

In electronics, electrical signals are pushed along wires, or small conductive traces that act like wires. The speed of these signals depend upon the ability of the conductor material to relay electromagnetic waves. While this speed is quite fast, it is often slow compared to the speed of light. For example: in a vacuum an electromagnetic wave can travel at the speed of light, in pure copper it can travel at about 96% of the speed of light, in a typical coax cable it travels at about 70% of the speed of light, in some circuit boards the speed is only 50% of the speed of light.

Ripples in the density of free electrons on the surface of a metal are called plasmons. Plasmon waves travel at the speed of light and at optical frequencies, which are high. Thin films of silver and nickel with ultrasmooth surfaces show promise for the development of plasmonic circuits and metamaterials.

Engineers study whether plasmonics, ‘light on a wire,’ is circuitry wave of future – [stanford.edu]

If data drove itself around in cars, photonics would be a roomy minivan and electronics would be a nimble coupe. Photonic components such as fiber optic cables can carry a lot of data but are bulky compared to electronic circuits. Electronic components such as wires and transistors carry less data but can be incredibly small.

A problem holding back the progress of computing is that with mismatched capacities and sizes, the two technologies are hard to combine in a circuit. Researchers can cobble them together, but a single technology that has the capacity of photonics and the smallness of electronics would be the best bridge of all. A new research group in Stanford’s School of Engineering is pioneering just such a technology—plasmonics.

Plasmonic computer chips move closer – [newscientist.com]

Computer chips capable of speeding data around by rippling the electrons on the surface of metal wires just got a step closer, researchers say.

Mark Brongersma, at Stanford University in Palo Alto, California, US has found a new way to model the three-dimensional propagation of these ripples – called plasmons – in two dimensions. He says the new model is much simpler and more intuitive than existing simulations and will be crucial in the design of plasmonic components for computer chips.

Plasmons travel at the speed of light and are created when light hits a metal at a particular angle, causing waves to propagate through electrons near the surface.

Plasmonics: Smooth operator – [nanowerk.com]

Surface plasmon resonance—the coherent excitation of free electrons on the surface of metals—is crucial to the operation of extremely small photonic devices, which have applications ranging from optoelectronic circuits and molecular sensors to the ‘metamaterials’ that could one day be used to make invisibility cloaks. To minimize scattering losses in metals, the metal surfaces need to be extremely smooth. Jinghua Teng at the A*STAR Institute of Materials Research and Engineering and co-workers have now developed an effective method to fabricate smooth thin films of silver with enhanced plasmonic properties (“Enhanced Surface Plasmon Resonance on a Smooth Silver Film with a Seed Growth Layer”).

SEE ALSO:
Metamaterials
Superlens
Naked Clothes
Nanowires

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